Why does the media persist in calling these "guerilla" attacks? They are terrorist attacks. They don't seek to win the war by making key strikes.
They mean to terrorize the local populace and Americans in their living rooms watching the nightly news. Keep the local Iraqis scared about working with the Americans and get the housewives to complain about putting troops at danger.
But if they could win back Iraq for Islamic power fanatics, I'll bet they would take it.